Royal Icing dried very funky

I am making Yo Gabba Gabba! cookies for my son's 1st birthday and to save time, I was thinking of making the characters as transfers to save time. Muno, a big red fella came out perfectly. His icing (three colors, red, black and white) dried perfectly smooth.

I am attaching the beggings of Foofa, a pink girl. I used Americolor's Deep Rose and Wilton RI mix (its the only think I have available here). My husband was the one in charge of coloring as he has a great eye for it. He started with the darker pink and lightened it by adding Wilton white. I don't know what we did wrong. I am attaching pictures, maybe someone here can advise me how to correct this?

I will say we have been having some rain here, so maybe humidity is a factor? I do have that tarter powder which I know can act as a stabilizer but I don't know how much to put in a batch.

In May I did some wedding cookies that were black and white. I made a batch of royal icing and colored 1/2 of it black with Americolor black coloring. The white was perfectly smooth on the cookie, but the black dried bumpy.

I've seen this happen before. Check out this post by Cookies and Cups: http://cookiesandcups.com/a-longhorn-story-royal-icing-woes/ If you read through the comments, you might get some ideas on what to troubleshoot.

I've had it happen before. I don't know the cause. It seemed like either there was too much coloring, it wasn't mixed enough, or it was just a bad batch. I made a new batch and the second batch worked fine.